Safety device for stamping-presses and the like



F. ALLEY.

SAFETY DEVICE FOR STAMPING PRESSES AND THE LIKE.

APPLICATION FILED JAN. 4, I921. 1,384,654, Patented July 12, 1921.

3 SHEETS-SHEET 1.

v F. ALLEY. SAFETY DEVICE FOR STAMPING PRESSES AND THE LIKE.

APPLICATION FILED JAN. 4, 192l- Patented July 12, 1921.

3 SHEETS-SHEET 2.

F. ALLEY.

S AFETY DEVICE FOR STAMPING PRESSES AND THE LIKE.

APPLICATION FILED IAN 4,192]. 1,384,654. Patented July 12, 1921.

3 SHEETS-SHEET 3.

WWW

UNITED STATES PATENT OFFICE.

FRANK ALLEY, OF WEST HARTFORD, CoNNECTICUT, ASSIGNOR, b THE ARROWELECTRIC COMPANY, OF HARTFORD, CONNECTICUT, A CORPORATION OF CON-NECTICUT.

SAFETY DEVICE FOR STAMPING-PRESSES AND THE LIKE.

Specification of Letters Patent.

Application filed January 4, 1921. Serial ltd 434,978.

To all whom it may concern Be it known that I, FRANK ALLEY, a citizen ofthe United States, residing in West Hartford, in the county of Hartford,State of Connecticut, have invented a certain new and useful Improvementin Safety Devices for Stamping-Presses and the like, of which thefollowing is a specification.

My invention consists of an improved safety device with a mechanicallyactuated lock for stamping presses and the like, to

prevent the dies from injuring the hands of the operator of the machine.

My invention is applicable to any machine where the operator alternatelyfeeds work to the machine and causes the mechanism to operate, but it ismore particularly applicable to stamping presses. I am aware that instamping presses provided with safety devices, locking mechanisms havebeen combined therewith, but all such devices have been controlled bythe actuating treadle. The safety shield has been so connected to theactuating treadle of the presses that the plunger die cannot descenduntil the shield is fully downbetween the operator and the dies. Withsuch devices the release of the treadle releases the safety shield andthe latter flies up, exposing the plunger die before the latter hascompleted its downward movement.

"This momentary exposure is the cause of accidents to the operatorshands. My invention consists of the provision of means whereby it ismechanically certain that the shield will be held down in safetyposition until the plunger die has completed its downward movement andis about, or has begun, to rise again. 1

In the accompanying drawings, Figure 1 is a side elevation of a stampingpress to which one form of my invention has been applied the shieldbeing shown in its safety position;

Fig. 2 is a front elevation of part of the press with the shield in itsnormal elevated inoperative position;

Fig. 3 is a horizontal section of the same press taken along line A A,Fig. 2;

Fig. 4 shows the details of part of my invention;

Fig. 5 is a horizontal section similar to Fig. 3, showing a modifiedform of construction.

Fig. 6 is a modified form of construction I of part of my invention.

I have indicated the frame of the press at 1, and the die bed at 2. Onthe die bed is bolted the die 3 and adjacent to the die bed is theoperators table 4. The moving or plunger die 5 is bolted in the gate orcrosshead 6 to which a reciprocating motion can be lmparted through theconnecting rod 7 and the crankshaft 8 by the flywheel 10, when theclutch 9 is thrown in.

In'a stamping press the flywheel is the only part continuously inmotion. To actuate the plunger die the operator must throw in the clutch9 by means of a suitable lever such as treadle 11, operating through theme dium of any suitable connections. The treadle is shown pivoted to theframe of the press and has hinged to it the lower end of rod 12. Theupper end of this rod actuates the safety device 13 which, in theconstruction shown, operates guard arms 14. These guard arms carry asafety shield 15 which is adapted, when in the down or safety position,to prevent the operator putting or leav- 1ng his hands within range ofthe plunger die. This safety device is pivoted on shaft 16 and, owing tothe spring 17, tends to return the safety shield 15 to the elevatedposition shown in Fig. 2.

To make-certain that safety shield 15 remains down in the safetyposition until the operation of the machine has passed beyond the dangerpoint, I provide the latch 18 ositloned to engage one guard arm 14. helatch is shown in' detail in Fig. 4. It is pivoted to the head 19 ofslide rod 20 by pin 21. In the slide rod 20 is the recess 22 containingthe compression spring 23 and sliding pin 24. This spring 23 presses thesliding pin 24 against latch 18 so as to tend to keep it in the path ofmovement of the guard arm 14. When the guard comes down to safetyposition its carrying arm pushes the latch back and as soon as the guardarm passes the latch, the spring pushes the slid- Patented July 12,1921.

one end of the tension spring 27. This 7 spring tends to keep the latchin engagement with the guard arm and alsoto keep the roller 28, on theupper end of the pivoted lever 25, bearing against cam 29. In this waythe latching means are controlled by a power-operated part of the pressmechanism.

Since the cam 29 is mounted on the crankshaft 8, it can be seen that thereciprocation of pivoted lever 25 and consequently the withdrawal fromand the return to engagement position with the guard arm of the latch 18will operate in positive connection with the plunger die. The cam is soset that the latch does not withdraw from the path of movement of theguard arm and allow the safety shield to be raised from safety positionby spring 17 until the plunger die has operated on the work in die 3 andis withdrawing from contact therewith.

In Fig. 5 I show a slightly different form of construction. The guardarm is still pivoted on shaft 16 but is mounted outside the frame ofthepress and there is only one arm, instead of two.

Fig. 6 illustrates a modified method of reciprocating the pivoted lever25. Instead.

of depending on a tension spring to make the lever bear against thesingle cam 29, I make the cam double and actuate it positively in bothdirections from the crankshaft 8.

I' do not wish to restrict myself to the details described, as they maybe readily modified without departing from my invention.

I claim as my invention:

1. A safety device for stamping presses and the like, comprising amovable safety shield in combination with a movable latch to lock theshield in safety position and in dependent means adapted to becontinuously controlled by a power-operated part of the press mechanismfor operating said latch.

2. A safety device for stamping presses and the like, comprising avertically movable safety shield in combination with a movable latch tolock the shield in safety position and independent means adapted to.

be continuously controlled by a power-op; erated part of the pressmechanism for operating said latch.

3. A safety device for stamping presses and the like, comprising amovable safety shield, a catch to lock it in safety position, and rotarycam means controlled by the power shaft of the press for releasing theshield at any desired point in the operation of the press.

4. A safety and the like, comprising a movable safety shield, a movablecatch to lock the shield in safety position, and means controlled by apower operated part of the press mechanism for unlocking the shield onlyafter the plunger die begins its return stroke.

5. A safety device for stamping presses and the like, comprising amovable safety shield, a movable catch to lock the shield in safetyposition, a slide rod adapted to reciprocate said catch out of and intolock ing position with the shield and rotary cam means controlled by apower operated part of the press mechanism for actuating said slide rod.

6. A safety device for stamping presses and the like, comprising amovable-safety shield, a slide having a catch to lock the shield insafety position, means to reci rocate said slide and its catch out ofand into locking position with the shield, said means comprising apivoted lever controlling said slide, a cam and a power-driven shaftcausmg said cam to reciprocate said pivoted lever.

In testimony whereof I have signed my name to this specification.

FRANK ALLEY.

device for stamping presses

